Carburetor



May 31.1921. y

- J. G. LANNING `CARBURETOR Filed July 3Q. 1920 2 Sheets-.Sheet 1V GWW/nap Patented MayV 31, l1927.

UNITED STATES 1,630,493 PATENT OFFICE.

'OHN G. LANNING, 0F DETROIT, MICJHIIGAN, ASSIGNOR T0 DETROIT IUBRICATOR COM- PANY, F DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN.

oAnBUREToR.

Application lecl .Tuly 30, 1920. Serial No. 400,087.

The invention relates to carburetors of opening to the fuel column -as the air valve moves towards open position. The retarding of the movement of the valve is either through its' own inertia' or through additional retarding means, such as a dashpot, and the resistance is adjusted to obtain as far as possible a constant proportion of fuel and air. It has, however, been found difficult to obtain any adjustmentawhich will insure proper acceleration of the vliquid withoutv such retarding of the movement of the air valve as to slow its response to the throttle.

It is the object of the present invention to obtain amore instantaneous acceleration of the fuel and with less retardation of the opening of the air valve. It is a further object to delay the re-est-ablishment of normal relation of the fuel to the air current to compensate for the inertia of the moving parts, or in other words, to synchronize .the operation of the nozzle with the acceleration of the motor. This I accomplish by means controlling the .passage of the fuel, which responds practically instantaneously to 'an increase in vacuum upon the fuel column, and increases the amount of fuel passing through the control orifice. Y More specilically, I have accomplished the desired result by the use of an accelerating plunger of small mass and having but a slight element of inertia, said plunger controlling the amount of fuel passing through the orifice and being exposed tothe high vacuum above the air valve.

In the drawings: l

Figure 1 is a vertical central section through a carburetor embodying my invention' f Y Ifiygiire 2 is an enlarged vertical ksectional view of the valve mechanism and as irating means and showinga slightly modi ed construction;

-Figure 3 is a cross-section on line 3-3 of Figure 1.

A is a casing containing the air inlet passage B, mixing chamber C, outlet D, and

controlling throttle E. F is the air valve l lwhich engages an annular seat G between the inlet B and mixing chamber C. H is the stem of the valve, which is guided in a bearing I and which atv its lower end is provided with a piston J operating in a cylinder K to forma dashpot. Centrally within this stem is the fuel passage L. There is also provided through the valve the aspirating passage N for causing the discharge of the fuel.

With the construction as thus far de- 'sc'ribed and as heretofore constructed, when the throttle is opened, .the increased vacuum in the mixing chamber `operating upon the aspiratng passage and liquid fuel nozzle will cause an acceleration in the movement of the fuelcolumn, while the inertia of the air valve together with the resistance of the dashpot, will delay the opening movement of the valve. Itis necessary, however, that the fuel should be accelerated, while the entra-nce orifice thereto is restricted, for increase in the size of this oriiceydoes not occur until after the air valve begins to move. -With my improved construction I have provided means for temporarily increasing the area of opening tothe fuel column, so as to decrease the resistance to the acceleration thereof. This, as shown, consists in a tubular member O'surrounding a control pin 'M and slidably arranged within the hollow stem H. The member O is yieldably held in normal position by ya spring P arranged between its upper end and a shouldenwithin the stem, while the lower end engages aV suitable stop such as Q. In the modiiication illustrated in Figure 2 the lower end of the sleeve rests` upon an apertured plate Y inserted in the piston J. With this construction the area of the opening orifice into the fuel column is determined by the relative positions of the member 0 and the control pin M and as the member 0 is carried by the valve stem I-I, its position is changed with the movement of the valve, so that it performs the same general function as :constructions of the type heretofore used.- :Whein however, the throttle-'is suddenly opened and a high vacuum is placed upon the fuel nozies zle, the increased dierential pressure on the lower end ofthe member O will move said member upward relative to the hollow stem H and control pin M, which will increase l the spring P will returnthe member O to its normal positionA determined by the stop Q.

The discharge and primary atomization of the li uidfuel is largely effected by the ejector e ect of the asplrating air passage through the valve. To increase this effect I have formed this aspira-ting passage as a modified venturi and in place of discharging the liquid vertically, it is discharged through a series of lateral portsvadjacentto the throat of the venturi in the plane of greatestsuction.

In detail, the valve F has a cap member R, which is fashioned with a Venturi passage therethrough which vat its lowerend is fe 'with air through ports S. in the body of the valve. T is a. nozzle fitting arranged atthe upper end of the stem H and extending into the throat of the Venturi passage,` the external surface of said fitting being fashioned.to conform to a portion of the Venturi passage. A hollow plug X isremovably positioned within the lowerend of the nozzle and extends below thesame in engagement with'the upper end of the spring U is a cap for closing the top of'the nozzle T, and V are a series of small ports, communicating with the interior of the nozlzle and discharging into the -throat of the venturi. This construction reduces a better atomization and commmgling of the liquid fuel with the air and also a better ejectoreiect for starting the discharge of fuel from the nozzle. i

The valve F is retarded in its movement by a. dashpot formed by the piston J in the cylinder K. It is desirable that the resistance should be greatest during the initial openingof the valve, which is accomplished by a c ose tit ofthe piston to the cylinder in position for initial opening and an increased clearance as the piston moves towardsopen position of the valve. Thusgas shown,.a tapering channel W is formed in one side of the cylinder which, after the piston'is lifted a certain distance, will progressively increase the opening through which the liquid' in the dashpot can pass 'from oneside of the piston to the other.

The lconstruction just described I do not broadly claiin a's my invention, but I have found that in combination with the features above,the carburetor as a whole is much. more sensitive and flexible in its operation.

4Means other than the specilic construction shown canl be employed for the same purpose. i

- In operation, whenever lthe throttle is suddenly opened, a high vacuum will be communicated tothe mixing chamber `C and through the ports V to the interior of the nozzle. This will cause an increased differential pressure on the lower end of the member O, as has been before described, which results in the raising of this member and the increasing of the entrance orifice to the liquid fuel column. The lupward movement of the valve F is delayed by its inertia and the resistance of the piston J, 'so that the high vacuum is maintained long enough to accelerate the fuel, while the initial move ment of the valve is greatlyretarded. As soon, however, as the piston has moved forward a short distance, the increased clearance afforded by the channel W will decrease the resistance and permit quick acceleration inthe movement of the valve.

The 'effect of the construction is not only to produce better acceleration, -birt also to accomplish proper deceleration. Thus when the'throttle is quickly'closed, 4the air valve will rapidly drop towards its seat and the proper mixture 'will be obtained during deceleration. l

What I cla-im as my invention is: In a carburetor, the combination with an automatic air valve having a liquid fuel passage through the stem thereof, of-a control pin arranged within said stem to regulate said passage, an independently movable sleeve surroundin said pin and withinsaid stem, said movab e sleeve cooperating with said control pin to .formv an inlet-orifice for said fuel passage and beine exposed to pressure below said orifice, said member being ofi small mass compared to the mass of said automatic air valve, yand movable by-diti`er ential pressure on the opposite sides of said inlet 'orifice to vary the opening of said orificeindependent and in advance of. the

,movement of said valve and yieldable re silient 4means between said' sleeve and .said

vvalve for permitting said independent movement end gradually restoring said sleeveto4 normal position. 1

In testimony whereof I ,'aflix my si nature.

JOHN IG. LAN NG. 

